This invention relates to a process for preparing chloromethyl group substitued heterocyclic compounds of use as intermediates in the manufacture of pharmaceutically active compounds. The invention also includes novel intermediates and the preparation of 2-chloro-1,1,1-tri(C.sub.1 -C.sub.6)alkoxyethane starting materials of use in the above process.
Prior art methods for the preparation of chloromethyl group substituted heterocyclic compounds include the reaction of ortho-aminophenol with chloroacetyl chloride in Hamer, J. Chem. Soc., 1480 (1956) resulting in a very poor yield of 6%, and the reaction of orthoaminothiophenol with chlroacetyl chloride in Japanese patent publication (Kokai) 77 66531. Another method is dislcosed in Saito et al., Synthesis, 102 (1979) wherein orthoaminophenol or orthoaminothiophenol is reacted with 1-chloro-2-amino-2-ethoxyethane. This reaction proceeds with satisfactory yields. However, on substitution of the benzene ring with 4-bromo, the desired 5-bromo-2-chloromethylbenzothiazole is not formed. Similarly, desired products are not obtained on reaction with the pyridine compounds of the formula ##STR3## wherein X is oxygen or sulphur.
According to the present process, satisfactory yields may be obtained in forming substitued and unsubstituted phenyl, pyridyl or pyrimidyl chloromethyl heterocyclics.